1. Field of the Invention
The present invention relates generally to air vents used in building structures, and more particularly to air vents having automatic damper operation apparatus, and still more particularly to a fire safety magnetically driven auto-closing vent for soffits and walls that connect the exterior of a building to its interior or that connect adjoining rooms in a building. The inventive apparatus prevents the rapid ingress of fire and fire gasses in buildings through the vents of a ventilating system.
2. Discussion of Related Art Including Information Disclosed Under 37 CFR §§1.97, 1.98
The 2007 wildfires in San Diego and Orange counties, California, have highlighted the vulnerability of commercial and residential structures to rapidly spreading wildfires. It has been observed that fires frequently enter structures through vents in attics, soffits and foundations, and that they may spread through buildings through wall vents. A highly publicized case described the destruction of an expensive home originally constructed to be effectively fireproof. Exterior walls of the house were covered with stucco and the roof was protected by roof tiles. However, these features failed to stop the complete destruction of the home by fire, as the fire easily entered the house through attic air vents exposing the interior of the house to the outside atmosphere. Once ignited, the dry interior of the attic burned uncontrolled and resulted in the complete destruction of the home and its valuable contents.
While this and other similar incidents highlight the problem of fire access through vents, there is as yet no commercially viable solution proposed to the problem. The present invention represents a solution by providing a vent having a magnetically driven, automatically closing damper, which is ordinarily retained by a thermal fuse that releases at a predetermined temperature. After release, the damper is secured in a locked and closed position with magnetic and mechanical latches.
Other fire damper vents are known. For instance, U.S. Pat. No. 6,676,508, to Graham, teaches a magnetically controlled air flow system having a pivotable flap with a permanent magnet at distal ends. Two coils with magnetizable cores are mounted inside the air duct and positioned so as to engage the permanent magnet when the flap is in either a closed or an open position. By energizing the coils, the permanent magnet is attracted to the magnetizable cores in either one of the coils, thereby actuating the flap between the closed and open positions.
U.S. Pat. No. 6,681,863, to Odelros, shows a method and apparatus for preventing distribution of fire gases in a ventilating system. The system detects and responds to pressure drops at a measuring point at the inlet side or the outlet side. When a significant low pressure is registered, the damper is closed to block air flow past the measuring spot.
Especially pertinent for the present case is U.S. Pat. No. 7,018,289, to Heil, et al., which describes a damper assembly having a damper blade kept in an open position by a fusible link connected to the damper blade. A biasing force tends to urge the damper blade to a closed position. The fusible link fails upon an occurrence of a predetermined condition. A damper mechanism is provided including a locking mechanism linked to the damper blade that resists opening of the damper blade when the blade has closed due to failure of the fusible link.
U.S. Pat. No. 4,080,978, to McCabe, discloses a rotating blade, smoke, fire and air control damper with spring closures attached on both inside and outside surfaces of the blades. The spring closures cooperate with a bimetallic heat sensing device to trigger the closing of the blades at a predetermined temperature. The spring closure means acts with opposing forces through the blade linkage to “snap” close the blades and to retain the blades in that position even in the presence of fires. The springs are mounted on bracket supports attached to inner and outer blade surfaces with the free ends attached to opposing alternate ends of the frame. The bimetallic link may be mounted to automatically reset when recycled.
U.S. Pat. No. 3,650,069, to Alley, teaches a fire damper blade latch mounted to swing on a horizontal axis between an open position and a closed position across either a horizontal or a vertical duct. The blade is normally held open by a fuse and is weighted to swing by gravity to closed position across the duct when released. The blade includes a latch is mounted on the outer side of the blade and strikes a catch as the blade closes. The latch plate weighs the plate to swing it into locked position behind the catch when the damper blade reaches closed position.
The foregoing patents reflect the current state of the art of which the present inventors are aware. Reference to, and discussion of, these patents is intended to aid in discharging Applicants' acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the above-indicated patents disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein.